Why did Rihanna back out of her Grammy performance? The singer’s reps blamed the last-minute cancelation on bronchitis, but there might have been a different reason.

According to TMZ, several Grammy-connected sources and insiders who were present during the “Work” singer’s rehearsals say she was upset. They claim she had a “meltdown” and was loud, angry, and displeased with the run-through before leaving Staples Center.

RiRi’s team, however, still says that medical reasons kept her off the stage. “Based on Rihanna’s examination, after Grammy rehearsal today, Rihanna’s doctor put her on vocal rest for 48 hours because she was at risk of hemorrhaging her vocal chords,” a rep from her camp said on Monday.

That same night, she posted a tweet to her Navy, saying that she was “so sorry” she “couldn’t be there,” but didn’t provide a reason for her absence.

Rihanna was part of a separate Grammy week performance, a tribute to Lionel Richie, just two days prior to Music’s Biggest Night. TMZ’s sources say that the singer sounded flawless at that event and “great” during her Grammy rehearsals.

Rihanna was set to perform “Kiss It Better” off her platinum album ANTI at Monday’s show. According to “Late Late Show” host James Corden, who was scheduled to introduce the performance, RiRi’s set was based around a fictional ’80s talk show called “As It Lays.” She was slated to don ’80s attire and sit down to answer questions from Corden on the faux 80s-talk-show set.